Axed minister now free to criticise:Newman

THE Queensland premier says his sacked assistant health minister will now be free to criticise government policy - from the backbench.

Campbell Newman sacked Dr Chris Davis just before the federal Budget was handed down on Tuesday night.

He said Dr Davis had breached the convention of cabinet solidarity after he publicly aired concerns about the government's changes to the state's crime and corruption watchdog and new work contracts for doctors.

Mr Newman has told reporters Dr Davis is a man of integrity and he hopes he remains in the Liberal National Party and is re-endorsed to stand again for the party in Stafford.

He said Dr Davis would now be free of the rules that govern cabinet ministers.

"He's not bound by that rule anymore," Mr Newman told reporters on Wednesday.

"And I think he'll be liberated by that, and that's a good thing."

He said he was yet to determine who would take over as assistant health minister.

Earlier, Treasurer Tim Nicholls and Transport Minister Scott Emerson said the premier did the right thing in sending a message about what was expected of ministers and assistant ministers.

"In those circumstances where the premier did clearly ask him whether he understood he'd stepped outside those boundaries ... it really left the premier with no alternative but to terminate his appointment as assistant minister," Mr Nicholls told the ABC.

He said Dr Davis had admitted he'd breached the convention, and had apologised for doing so.

Opposition Leader Annastacia Palaszczuk said the timing of the announcement was clearly designed to limit political damage.

"It shows how weak the premier is, and it also shows this premier will not tolerate anyone's views other than his own," she said.

"I think he's using Dr Davis to send a message to all his backbenchers - and some of them certainly are nervous and a bit anxious at the moment - don't dare speak out, or look out," Mr Wellington told the ABC.

Opposition Leader Annastacia Palaszczuk believes the sacking will be followed by a wider cabinet reshuffle ahead of next year's state election.

"Unfortunately Chris Davis has felt the brunt of Campbell Newman when Campbell Newman has stood by other ministers in the past, it doesn't add up, it doesn't stack up," she told reporters.